Speech recognition systems have been under development for years and commonly used. However, a need continues to exist for improved accuracy.
It is known in the prior art to input audio data 10 to a front end 12 which extracts feature data. These feature data are input fed into a decoder 14, which with the help of an acoustic model 16 and a language model 18, outputs HYPs, the hypothetical sentence(s), HYPs consist of a series of words, such as in this document.
It is known to use a post decoder 20 to output a word confidence score, WCS, which is a measure of the confidence degree of a word/HYP. It is widely known in speech recognition to use a sentence/phrase confidence score to accept or reject phrases or sentences entirely. A more detailed description of prior development is shown in U.S. Pat. No. 6,959,278, which is incorporated by reference.